MAT2600 Metals Exam
Study Guide
What are structure-property (S-P) relations? - Answer mathematical expressions thaat
embodies the functional dependence on properties on material structure
What is a constitute relation? - Answer a mathematical description of the response of a
material to some applied stimuli
such relations are material dependent
What are the S-P relations dependent on? - Answer material, manufacturing and
performance
What is the definition of strain? - Answer ratio of extension to length
What is the definition of stress? - Answer force per area
What is the yield stress? - Answer after this stress the material doesn't return to its
original shape
What is the plastic strain? - Answer the permanent strain on a material when loaded
above the yield stress
What is the total stress tensor made up of? - Answer a hydrostatic stress tensor, pmI
and deviatoric stress tensor, S
I is the identity matrix
What does the hydrostatic stress tensor involve? - Answer only involves pure tensile or
compressive stress componenets
What does the deviatoric stress tensor represent? - Answer the shear stresses of the
the total stress state
What is the strain tensor made up of? - Answer the hydrostatic strain tensor ∈mI and a
deviatoric strain tensor ∈'
I is the identity matrix
What does the hydrostatic strain cause? - Answer volume changes
Whaat does the deviatoric strain cause? - Answer changes in shape
What is the yield surface? - Answer a line connecting all loci of stress point that cause
plasticity
, the elastic-plastic transition of the material
What is the normality condition? - Answer d∈p α n
the plastic strain increment induced at a point on the yield surface is related to the
normal n (vector) of the yield surface
What doe the function f(σ) (yield stress) convert any stress state tensor σ in stress space
to? - Answer an effective stress, sigma bar
What does the yield surface depend on? - Answer the material microstructure
What is the maximum strain? - Answer the failure strain, ∈f
measures the ductility of the material
What are polycrystals? - Answer a collection of crystals - called grains - that are joine
together
What is a crystal lattice? - Answer a repetitive 3d pattern
e.g. simple cubic, hexagonl, face centred cubic (FCC), body centred cubic (BCC)
What are crystal defects? - Answer disruptions in the periodicity of the crystal lattice
arrangement
What are point defects? - Answer vacancies, interstitial and substitutional atoms
What are line defects (1-dimensional)? - Answer dislocations
What are surface defects (2-dimensional)? - Answer twins, staking faults, grain
boundaries
What are volume defects? - Answer voids, cracks, foreign inclusions
What do point defects induce in a lattice? - Answer local distortions of the lattice, which
have hydrostatic and deviatoric contributions
these will result in straining of the crystaal which will induce a stress field
thus, point defects have aan associated self-state of stress and strain
What is the Burger's vector? - Answer the vector needed to close the circuit around a
dislocation from its final point F to the starting point S
What does the Burger's circuit measure? - Answer the total Burgers vector inside the
contour
What is an edge dislocation? - Answer Burgers vector is perpendicular to the
dislocation line (tangent vector)
What is a screw dislocation? - Answer Burgers vector parallel to dislocation line
Study Guide
What are structure-property (S-P) relations? - Answer mathematical expressions thaat
embodies the functional dependence on properties on material structure
What is a constitute relation? - Answer a mathematical description of the response of a
material to some applied stimuli
such relations are material dependent
What are the S-P relations dependent on? - Answer material, manufacturing and
performance
What is the definition of strain? - Answer ratio of extension to length
What is the definition of stress? - Answer force per area
What is the yield stress? - Answer after this stress the material doesn't return to its
original shape
What is the plastic strain? - Answer the permanent strain on a material when loaded
above the yield stress
What is the total stress tensor made up of? - Answer a hydrostatic stress tensor, pmI
and deviatoric stress tensor, S
I is the identity matrix
What does the hydrostatic stress tensor involve? - Answer only involves pure tensile or
compressive stress componenets
What does the deviatoric stress tensor represent? - Answer the shear stresses of the
the total stress state
What is the strain tensor made up of? - Answer the hydrostatic strain tensor ∈mI and a
deviatoric strain tensor ∈'
I is the identity matrix
What does the hydrostatic strain cause? - Answer volume changes
Whaat does the deviatoric strain cause? - Answer changes in shape
What is the yield surface? - Answer a line connecting all loci of stress point that cause
plasticity
, the elastic-plastic transition of the material
What is the normality condition? - Answer d∈p α n
the plastic strain increment induced at a point on the yield surface is related to the
normal n (vector) of the yield surface
What doe the function f(σ) (yield stress) convert any stress state tensor σ in stress space
to? - Answer an effective stress, sigma bar
What does the yield surface depend on? - Answer the material microstructure
What is the maximum strain? - Answer the failure strain, ∈f
measures the ductility of the material
What are polycrystals? - Answer a collection of crystals - called grains - that are joine
together
What is a crystal lattice? - Answer a repetitive 3d pattern
e.g. simple cubic, hexagonl, face centred cubic (FCC), body centred cubic (BCC)
What are crystal defects? - Answer disruptions in the periodicity of the crystal lattice
arrangement
What are point defects? - Answer vacancies, interstitial and substitutional atoms
What are line defects (1-dimensional)? - Answer dislocations
What are surface defects (2-dimensional)? - Answer twins, staking faults, grain
boundaries
What are volume defects? - Answer voids, cracks, foreign inclusions
What do point defects induce in a lattice? - Answer local distortions of the lattice, which
have hydrostatic and deviatoric contributions
these will result in straining of the crystaal which will induce a stress field
thus, point defects have aan associated self-state of stress and strain
What is the Burger's vector? - Answer the vector needed to close the circuit around a
dislocation from its final point F to the starting point S
What does the Burger's circuit measure? - Answer the total Burgers vector inside the
contour
What is an edge dislocation? - Answer Burgers vector is perpendicular to the
dislocation line (tangent vector)
What is a screw dislocation? - Answer Burgers vector parallel to dislocation line
